Hi, I know this has been done but a quick read through on here does not seem to address the household discussion we had on this topic. The mythbudgets claimed to have defeated Newtons laws by putting a sail on one end of a fan boat and turning the fan around. I predicted it would not work, but by the end of the show the boat appears to be pulled along by the sail, albeit slowly. Reading the existing thread I could not see the explanation I landed upon as follows, perhaps you can tell me why I am wrong. The boat is being propelled by atmospheric pressure. The moving body of air between the fan and the sail has a lower pressure relative to the still air around the boat at right angles to the flow of air to the sail. As a consequence the air around the boat rushes into the space and results in increased mass pushing on the sail.